This invention relates to a measurement system for machine parts of the type which includes an apparatus for displaying visually an indication of a measurement and particularly to an apparatus that is responsive to an electrical signal that provides a visible display utilizing binary segment devices of one form or another known in the art as devices having at least two optically visible states.
There are in the prior art a number of devices which digitally indicate measurements as, for example, a micrometer as seen in U.S. Pat. No. 3,924,336 and height gages as seen in U.S. Pat. Nos. 3,924,337 and 4,037,325. Devices such as this are fine when a fixed part is to be measured but fall short of the desired result when a part is moving at a high rate for the decimal numerals will be changing so rapidly that they cannot be followed by the eye. This forces the operator to slow the machinery down to a point where he can make a visual indication with some accuracy and/or see the range variation that is occuring.
There are also a number of devices in the prior art that provide visible displays which are representative of various phenomena. For example, there are prior art devices that will display time which have been suggested in Patents such as U.S. Pat. No. 3,772,874. Devices such as this, however, are for purely disclosing time and even when analog indications are combined with digital indication, the analog digital indications are not equivalent one to the other. In the prior art the only disclosure of an analog indication which is identical to the digital indication is contained in U.S. Pat. No. 3,696,385.